Rendering Natural Bokeh Effects Based on Depth Estimation to Improve the Aesthetic Ability of Machine Vision

Abstract

Machine vision is the key to realizing computer-vision tasks such as human–computer interaction and autonomous driving. However, human perception of an image’s beauty is innate. If a machine can increase aesthetic awareness, it will greatly improve the comfort of human perception in human–computer interaction. The bokeh effect is one of the most important ways to improve the artistic beauty of photographic images and the image aesthetic quality. Bokeh rendering of an image can highlight the main object of the image and blur unnecessary or unattractive background details. The existing methods usually have unrealistic rendering effects with obvious artifacts around the foreground boundary. Therefore, we propose a natural bokeh-rendering method based on depth estimation that satisfies the following characteristics: objects in the focal plane are clear and out-of-focus objects are blurred; and the further away from the focal plane, the more blurred the objects are. Our method consists of three modules: depth estimation, background subdivision, and bokeh rendering. The background-subdivision module can select different focal planes to obtain different blur radii, making the bokeh-rendering effect more diverse, so that it does not oversegment objects. The bokeh-rendering module adjusts the degree of bokeh by adjusting the blur-radius factor. In the experimental section, we analyze the model results and present the visualization results.